partial drying lumber

[Steve Morse]

we are trying to free up time in our continuous kiln when drying 6x6 SYP. Thinking of partial drying then letting them air dry for some time and return to kiln if needed. Looking for feedback on this. I feel it may be more difficult to complete the drying if returned to the Kiln? Looking for around 18-20%

[GeorgeCulp]

If you partially dry and then let them air dry the balance you will obviously save time in your kiln. However, if you have to "redry" there will be involvement of loading and unloading those 6x6's for a second time.

Also, its not clear whether the total time in the kiln will be greater or less than if you ran them to full dryness initially. The reason they may take less total time is that after having partially dried them they will equalize and therefore the remaining moisture will be easier to remove as it will be closer to the surface.

But... you will have to heat the 6x6's up again to get the moisture to mobilize and that will take a while.

Those are just somethings to think about. 

(Just between me and you and the fence post... and if kiln time and loading wasn't an issue..... I feel that partially drying the 6x6's in the kiln..... and then allowing them to sit outside until fully equalized....... and then putting them back in the kiln to be finished..... will result in a more quality dried timber with  more uniform moisture gradient from surface to core.